docs: def _post(self, url, data):
          """
          Helper method: POST data to a given URL on TBA's API.
  
          :param url: URL string to post data to and hash.
          :pararm data: JSON data to post and hash.
          :return: Requests Response object.
  
          """
          return self.session.post(self.WRITE_URL_PRE + url % self.event_key, data=data, headers={'X-TBA-Auth-Sig': md5((self.auth_secret + '/api/trusted/v1/' + url % self.event_key + data).encode('utf-8')).hexdigest()})